Photoresist composition and associated method of forming an electronic device

Abstract

A photoresist composition includes a first polymer in which at least half of the repeat units are photoacid-generating repeat units, and a second polymer that exhibits a change in solubility in an alkali developer under the action of acid. In the first polymer, each of the photoacid-generating repeat units comprises photoacid-generating functionality and base-solubility-enhancing functionality.

The invention claimed is: 
     
       1. A photoresist composition comprising:
 a first polymer comprising, based on 100 mole percent of total repeat units, 60 to 100 mole percent of photoacid-generating repeat units; wherein each of the photoacid-generating repeat units comprises an anion, a photoacid-generating cation, and base-solubility-enhancing functionality; wherein either the anion or the photoacid-generating cation is polymer-bound; wherein the base-solubility-enhancing functionality is selected from the group consisting of tertiary carboxylic acid esters, secondary carboxylic acid esters wherein the secondary carbon is substituted with at least one unsubstituted or substituted C 6-40  aryl, acetals, ketals, lactones, sultones, alpha-fluorinated esters, beta-fluorinated esters, alpha,beta-fluorinated esters, polyalkyleneglycols, alpha-fluorinated alcohols, and combinations thereof; and wherein each of the photoacid-generating repeat units independently has the structure 
 
       
         
           
           
               
               
           
         
         wherein
 m is independently in each photoacid-generating repeat unit 0 or 1; 
 n is independently in each of the repeat units 0 or 1; 
 q is independently in each photoacid-generating repeat unit 0, 1, 2, 3, 4, or 5; 
 r is independently at each occurrence in each photoacid-generating repeat unit 0, 1, 2, 3, or 4; 
 L 1  is independently at each occurrence an unsubstituted or substituted C 1-20  hydrocarbylene, wherein the substituted C 1-20  hydrocarbylene can, optionally, comprise one or more in-chain divalent heteroatom-containing groups that is —O—, —S—, —NR 4 , —PR 4 —, —C(O)—, —OC(O)O—, —N(R 4 )C(O)—, —C(O)N(R 4 )—, —OC(O)N(R 4 )—, —N(R 4 )C(O)O—, —S(O)—, —S(O) 2 —, —N(R 4 )S(O) 2 —, —S(O) 2 N(R 4 )—, —OS(O) 2 —, or —S(O) 2 O—, wherein R 4  is H or C 1-12 hydrocarbyl; 
 L 2  is independently at each occurrence —O—, —C(O)—, or —N(R 5 )—, wherein R 5  is H or C 1-12  hydrocarbyl; 
 L 3  is independently at each occurrence an unsubstituted or substituted C 1-20 hydrocarbylene, wherein the substituted C 1-20  hydrocarbylene can, optionally, comprise one or more in-chain divalent heteroatom-containing groups that is —O—, —S—, —NR 4 , —PR 4 —, —C(O)—, —OC(O)O—, —N(R 4 )C(O)—, —C(O)N(R 4 )—, —OC(O)N(R 4 )—, —N(R 4 )C(O)O—, —S(O)—, —S(O) 2 —, —N(R 4 )S(O) 2 —, —S(O) 2 N(R 4 )—, —OS(O) 2 , or —S(O) 2 O—, wherein R 4  is H or C 1-12  hydrocarbyl; 
 R 1  is independently at each occurrence in each photoacid-generating repeat unit halogen, unsubstituted or substituted C 1-40  hydrocarbyl, or unsubstituted or substituted C 1-40  hydrocarbylene; 
 R 3  is independently at each occurrence H, F, —CN, C 1-10  alkyl, or C 1-10 fluoroalkyl; 
 X is independently in each photoacid-generating repeat unit a single bond, —O—, —S—, —C(═O)—, —C(R 2 ) 2 —, —C(R 2 )(OH)—, —C(═O)O—, —C(=O)N(R 2 )—, —C(═O)C(═O)—, —S(═O)—, or —S(═O) 2 —, wherein R 2  is independently at each occurrence hydrogen or C 1-12  hydrocarbyl; and 
 
         a second polymer that exhibits a change in solubility in an alkali developer under the action of acid. 
       
     
     
       2. The photoresist composition of  claim 1 , wherein the photoacid-generating repeat units are derived from a single monomer. 
     
     
       3. The photoresist composition of  claim 1 , wherein the photoacid-generating repeat units are derived from at least two different monomers. 
     
     
       4. The photoresist composition of  claim 1 , wherein the base-solubility-enhancing functionality is a tertiary carboxylic acid ester, an acetal, a ketal, a lactone, or a combination thereof. 
     
     
       5. A photoresist composition, comprising:
 a first polymer comprising a homopolymer of 5-(4-methoxy-3-(4-((2-methyladamantan-2-yl)oxy)-1-(2-((2-methyladamantan-2-yl)oxy)-2-oxoethoxy)-1,4-dioxobutan-2-yl)phenyl)-dibenzothiophenium 1,1-difluoro-2-(methacryloyloxy)ethanesulfonate, a homopolymer of 5-(4-methoxy-3-(4-(((1R,3 S,5r,7r) -2-methyladamantan-2-yl)oxy)- 1-(2-(((1R,3S,5r,7r)-2-methyladamantan-2-yl)oxy)-2-oxoethoxy)-1,4-dioxobutan-2-yl)phenyl)-5H-dibenzo[b,d]thiophen-5-ium 1,1-difluoro-2-(2-(methacryloyloxy)acetoxy)ethanesulfonate, a homopolymer of 5-(4-methoxy-3-(2-(2-(((1R,3S,5r,7r)-2-methyladamantan-2-yl)oxy)-2-oxoethoxy)-2-oxo-1-(2-oxotetrahydrofuran-3-yl)ethyl)phenyl)-5H-dibenzo[b,d]thiophen-5-ium 1,1-difluoro-2-(methacryloyloxy)ethanesulfonate, a copolymer of 5-(4-(2-(2-methoxyethoxy)ethoxy) -3,5-dimethylphenyl)-5H-dibenzo[b,d]thiophen-5-ium 1,1-difluoro-2-(methacryloyloxy)ethanesulfonate and 5-(4-methoxy-3-(4-(((1R,3S,5r7r)-2-methyladamantan-2-yl)oxy)-1-(2-(((1R,3S, 5r,7r)-2-methyladamantan-2-yl)oxy)-2-oxoethoxy)-1,4-dioxobutan-2-yl)phenyl)-5H-dibenzo[b,d]thiophen-5-ium 1,1-difluoro-2-(2-(methacryloyloxy)acetoxy)ethanesulfonate, a copolymer 5-(4-(2-(2-methoxyethoxy)ethoxy)-3,5-dimethylphenyl)-5H-dibenzo[b,d]thiophen-5-ium 1,1-difluoro-2-(methacryloyloxy)ethanesulfonate, or 5-(4-methoxy-3-(2-(2-(((1R,3S,5r,7r)-2-methyladamantan-2-yl)oxy)-2-oxoethoxy)-2-oxo-1-(2-oxotetrahydrofuran-3-yl)ethyl)phenyl)-5H-dibenzo[b,d]thiophen-5-ium 1,1-difluoro-2-(methacryloyloxy)ethanesulfonate; and 
 a second polymer that exhibits a change in solubility in an alkali developer under the action of acid. 
 
     
     
       6. The photoresist composition of  claim 1 ,
 wherein each of the photoacid-generating repeat units of the first polymer has the structure 
 
       
         
           
           
               
               
           
         
       
       wherein m, q, r, L 2 , L 3 , R 1 , R 3 , and X are defined as in  claim 1 ; and
 wherein the second polymer comprises 10 to 65 mole percent of acid-labile repeat units, 0 to 50 weight percent of base-labile repeat units, 0 to 40 mole percent of base-soluble repeat units, and 0 to 15 mole percent of photoacid-generating repeat units; and 
 wherein the photoresist composition comprises, on a dry weight basis,
 20 to 80 weight percent of the first polymer, 
 10 to 60 weight percent of the second polymer, and 
 0.5 to 10 weight percent of a quencher. 
 
 
     
     
       7. A method of forming an electronic device, comprising:
 (a) applying a layer of the photoresist composition of  claim 1  on a substrate; 
 (b) pattern-wise exposing the photoresist composition layer to activating radiation; and 
 (c) developing the exposed photoresist composition layer to provide a resist relief image.